Installing a new bathroom is one of the most satisfying home improvements you can make, but it’s also one where people have the most questions before they get started, especially around the plumbing side of things. How long will it take? Do you need building regulations sign-off? Can you move the toilet?

Here are the plumbing questions we hear most often, answered as clearly as possible. For more general bathroom renovation questions, read this guide by the Federation of Master Builders.

 

How long does a bathroom installation take?

The honest answer is that timelines for bathroom installations can vary quite a bit depending on the scope of the work. A straightforward swap of an existing suite, with fixtures staying in roughly the same positions, can take two to three days.

If you’re moving pipework, changing the layout, or having new flooring and tiling done, it’ll be more like one to two weeks. The more extensive the plumbing changes, the longer it will take. Moving a toilet, for example, means rerouting waste pipes, and that takes considerably longer.

If you’re working with a team that handles the full project, including tiling and flooring through trusted trade contacts, there will be fewer headaches, and timelines will be shorter than when you’re coordinating multiple contractors independently.

Our bathroom fitting team manages the plumbing and heating elements, and has a network of trusted traders to handle the rest, so you only need one point of contact for your renovation.

 

Do I need building regulations approval for a bathroom renovation?

For a like-for-like revamp where the suite is being updated but nothing is moving, building regulations are unlikely to be required. However, for anything involving new drainage connections, structural changes, or a new bathroom being added where one didn’t previously exist, building control approval will be needed.

When it comes to electrics, under Part P of the Building Regulations, any significant electrical work in a bathroom, such as installing a new electric shower or adding circuits, must be carried out by a qualified electrician registered with an approved scheme like NICEIC or ECA. This applies across England and Wales. If you ever sell the property, solicitors will ask for the relevant certificates.

If you’re unsure whether your project needs sign-off, it’s always a good idea to check with your local authority’s building control department.

 

 

Can I move the toilet or sink to a different position?

Yes, but it’s not a simple change. Moving a toilet means relocating the soil pipe, which needs to run at the correct angle to drain properly. This can mean lifting floorboards, rerouting pipework through walls, and sometimes significant structural work, depending on the layout of the house. Sinks are a little more flexible, but they still need a properly routed waste pipe and a supply connection.

How much disruption is involved will vary depending on the layout of your existing bathroom and where the new position sits in relation to the main drainage stack. A good bathroom fitter will assess this during the design stage, so you’re not hit with surprises halfway through the project.

 

What should I think about during the bathroom design stage?

Layout is the obvious starting point when considering bathroom design, but there are other factors to consider:

• Shower type: Mains-fed showers are usually more powerful because they draw directly from your central heating system. Electric showers only heat water on demand, so they are more economical. The right choice for you will depend on your water pressure and personal priorities.
• Radiators and towel rails: These need to be planned as part of the heating setup, not added as an afterthought. Too often, these are forgotten until there is no space for them.
• Storage and accessories: Taps, furniture, mirrors and shaving points should all be factored into the bathroom design budget early, because they can add up.
• Ventilation: Building regulations require new bathrooms to have adequate extraction. A fan that runs for 15 minutes after the light is switched off is a standard minimum.

We always advise that you have your designs checked by a professional with knowledge of plumbing and heating, so they can flag anything you have missed.

 

Do I need a specialist bathroom fitter, or will any plumber do?

A bathroom installation involves more than just plumbing. You need someone who understands the heating system, can handle waste and supply connections properly, and has experience coordinating the other trades involved.

That doesn’t mean every job needs a large team, but it does mean that bathroom fitters with experience in full installations will produce a better result than a general handyman working from scratch. Our plumbing services cover everything from minor leaks to complete bathroom installations, with engineers who have been doing this work for decades.

 

How much does a bathroom installation cost?

Of course, costs will depend greatly on the size of the bathroom, the quality of the suite, and how much the layout is changing. A basic bathroom renovation in the Bristol area can start from around £2,000–£3,000 for a straightforward like-for-like replacement, with more complex projects going considerably higher.

If the cost feels like a lot upfront, don’t panic. Finance options are available, including 0% interest-free periods and longer-term monthly payment plans, so a new bathroom isn’t as out of reach as it may seem.

 

Can I add a new bathroom or en-suite?

Converting a bedroom, a large landing cupboard, or unused loft space into a bathroom or en-suite is a fairly common project, and the results can make a real difference to the functionality of the house, especially for family and student homes with only one bathroom.

The main considerations are drainage and water supply. A new bathroom needs to connect to the existing foul drainage system, and the pipework needs to run at the correct gradient to drain properly. How straightforward that is depends on where in the house the new bathroom is going and how close it is to the existing drainage stack.

Building regulations approval will be required. This will cover the drainage connections, ventilation, and any electrical work involved.

As for water supply, if you want a mains-fed shower in a new en-suite, the existing system needs to be able to handle the additional demand. Again, a plumber can assess this early on.

If this is something you’re considering, it’s worth having a conversation with a bathroom fitter and plumber early in the process, before you’ve settled on a layout. Small decisions at the design stage, like where the door goes or which wall the shower sits on, can have a big impact on how complex and costly the plumbing turns out to be.

 

 

A few other frequently asked questions

Are there guarantees or warranties for bathroom installation work?

This varies depending on who carries out the work and what products are used. At DHS, our installations are backed by manufacturer warranties and our workmanship is fully covered. Always ask your bathroom fitter for written confirmation of what’s covered and for how long before the work starts.

 

What happens to my water supply during a bathroom installation?

For most of the work, your water supply can be turned off in short bursts. A good installer will plan for this to cause as little disruption as possible. If there’s likely to be a longer period without supply, for example when main pipework is being rerouted, you will be made aware in advance so you can plan around it.

 

Do I need planning permission?

For most bathroom renovations, no. Planning permission is usually only required if the property is listed, or if work involves a new extension.

 

Can I do any of the plumbing work myself?

Some minor work, like replacing tap washers or a showerhead, is fine to DIY. But anything involving new waste connections, supply pipework, or electrical work in the bathroom should be done by a qualified professional. Non-compliant work can affect your home insurance and cause problems when selling, not to mention the likelihood of faults and issues down the line.

 

Ready to get started?

Whether you’re already planning a full bathroom renovation or just want to see if it is an option for you, our team is happy to help. We’ve been installing bathrooms across Bristol, Bath and North Somerset for over 40 years, and our first-class design and installation service is often significantly better value than many household names. Use our contact form or give us a call on 0117 924 7200 or to request a free, no-obligation quote, or to ask us any questions we’ve not covered here.